| Landslide disasters are serious in China,and there are many disaster types,complex disaster factors and abundant research achievements.However,the research on one kind of special acid erosion environmental landslide has not been in-depth.Xujiaping slope is located at K39+200m of Mianmao Highway under construction.The slope contains black shale.Acid production from black shale will lead to acid erosion and deterioration of adjacent rock mass and weakening of slope stability.The study on the mechanical properties of the slope is a supplement to the related research on slope stability degradation under acidic environment,and can also provide some suggestions for the prevention and control of disaster for the construction and operation of Mianmao Highway,and provide some reference for the study on slope instability process under similar acidic environment.In this paper,xujiaying slope was taken as the research object,and a detailed field geological survey was carried out by uav tilt photography and 3d slope reconstruction technology,to obtain the slope structure and acid erosion development characteristics,such as rock layer structure information,structural plane distribution parameters,rock mass acid erosion characteristics,acid erosion environment characteristics.Field test or sampling for physical and mechanical parameters of rock mass,combined with "Rock mechanics Parameter Manual" and engineering geology analogy method to make certain conversion and correction,in order to obtain the strength parameters of rock mass;The 3d discrete element software3 DEC was used to build the comprehensive model of slope rock mass and structural plane.After trial calculation and verification,the model was converted to UDEC for further static and dynamic numerical simulation analysis,to explore the changes of slope mechanical characteristics before and after shale acid erosion and deterioration under natural and seismic conditions.According to the comparison of simulation results,it is found that the interbedded structure of limestone and shale is the weak layer in the slope,and the mechanical response of slope displacement,stress and velocity are affected by it.The displacement distribution is bounded by the weak layer,and the rock mass above the weak layer has a larger overall displacement.The rock mass displacement is the largest in the place where the overburden rock is the weakest in the middle and lower part of the slope under earthquake action,and has a strong trend of being crushed and destroyed.The shear stress distribution extends along the soft layer,and the overall shear stress is large.There is a concentrated shear stress area extending along the soft layer in the middle and lower part of the slope under earthquake action,and the slope is prone to shear failure in this area.The velocity distribution also has a large velocity region in the middle and lower part of the slope.It is also found that after acid erosion and deterioration of shale,it takes longer time for slope to stabilize naturally,the differential internal force of slope is larger,and the displacement difference of rock mass above and below the weak layer is further increased.The displacement difference of the upper rock mass in the same position before and after shale acid erosion exists,and the displacement difference is more significant under earthquake action. |
